command: Prefer uint8_t* for buffers; prefer uint8_fast_t for lengths

Prefer using 'uint8_t' buffers as it is too easy to run into C sign
extension problems with 'char' buffers.  Prefer using 'uint_fast8_t'
for buffer lengths as gcc does a better job compiling them on 32bit
mcus.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 3 insertions, 4 deletions

diff --git a/src/avr/usbserial.c b/src/avr/usbserial.c
index ac60e087..6dbe4f0d 100644
--- a/src/avr/usbserial.c
+++ b/src/avr/usbserial.c
@@ -10,8 +10,7 @@
 #include "command.h" // command_dispatch
 #include "sched.h" // DECL_INIT
 
-static char receive_buf[MESSAGE_MAX];
-static uint8_t receive_pos;
+static uint8_t receive_buf[MESSAGE_MAX], receive_pos;
 
 void
 usbserial_init(void)
@@ -51,7 +50,7 @@ void
 console_task(void)
 {
     console_check_input();
-    uint8_t pop_count;
+    uint_fast8_t pop_count;
     int8_t ret = command_find_block(receive_buf, receive_pos, &pop_count);
     if (ret > 0)
         command_dispatch(receive_buf, pop_count);
@@ -65,7 +64,7 @@ void
 console_sendf(const struct command_encoder *ce, va_list args)
 {
     // Generate message
-    static char buf[MESSAGE_MAX];
+    static uint8_t buf[MESSAGE_MAX];
     uint8_t msglen = command_encodef(buf, ce, args);
     command_add_frame(buf, msglen);